Why do people mess with ```serializersModule = SerializersModule { polymorphic( CampaignC...

# serialization

[ursus]

Why do people mess with

serializersModule = SerializersModule {
    polymorphic(
      CampaignContent::class,
      CampaignContent.PopupModal::class,
      CampaignContent.PopupModal.serializer(),
    )
    polymorphic(
      CampaignContent::class,
      CampaignContent.Link::class,
      CampaignContent.Link.serializer(),
    )
  }

when serialzing `sealed class`es?

mine work just by annotating the sealed class & it's children

am I missnig something?